Latch for safety hooks



NOV. 30, 1937- R HERTEL 2,100,779

LATCH FOR SAFETY HOOKS Filed May 6, 1936 2 sheets sheet l Richard A. fierre/ IN V EN TOR.

ATTORNEYS.

NOV. 30, 1937. HERTEL 2,100,779

LATCH FOR SAFETY HOOKS Fild May 6, 1936 2 sheets sheet 2 IN VEN TOR.

A TTORNEYS.

Patented Nov. 30, 1 937 i UNITED STATES PATENT OFFICE LATCH FOR SAFETY HOOKS Richard K. Hertel, Vernon, Calif., assignor to Byron Jackson 00., Huntington Park, Calif., a corporation of Delaware Application May 6, 1936, Serial No. 78,185

5 Claims. (Cl. 29483) 7 This invention relates to rotary and casing lower end of shank 4 by a cross pin H. In the hooks such as are employed for raising and lowpresent instance the hook body is provided with ering drill pipe or casing in an oil well. More a pair of oppositely disposed elevator link supparticularly, the invention relates to improveporting arms, one of which is shown at It. These 5 ments in looking devices for latch links in hooks arms are at a right angle to the bill of the hook 15. of the type shown in U. S. Patent No. 1,825,018 and are provided with links 15 which close the issued Sept. 29, 1931, to Nelson K. Smith. entrance to the arms l3. Each link [5 is pro- In the hook illustrated in Patent No. 1,825,018, violed with locking means i! and [9. The hook there is a hook member ll having a body 43, with body 9 has a forwardly extending bill 21 forming a forwardly extending bill forming a bail-rea bail-receiving notch 23. Pivoted to the end of 1.0 ceiving notch 4| and a latch link arm 44 pivoted the bill 2! is a latch link arm 25. The pivot pin to the end of the bill and adapted to engage a iS show at The upp end of arm 25 is protrusion 58 formed on the body 43 above the Vided With a head 9 adap to engage a p notch 4| so that art of the load n th h ok sion 30 formed on the body. The arm 25 is formed will be carried by the latch link arm 44 and the with a channel portion 32 adapted to receive latch 15 protrusion 5a. The latch link arm 42 i provided bolt and latch lock. The arm is provided at with a safety locking device comprising a sliding its lower end with an inwardly extending finger latch bolt 51 yieldably supported on a coil com- 6 dapte t be eng y a bail 28 ns e in pression spring 62. The'movement of the latch notch 23 to automatically close the latch link bolt 51 is in substantially a vertical plane pararm 25. 2,0

allel to the vertical axis of the hook. With a lock The atc p s s a latch b 34 pp d of the type described above, there is the posupon a substantially vertical coil compression sibility, under certain conditions, of accidentally Spring d an -a y latoh look 33 pivotally releasing the latch link arm 44. For example, mounted on the latchbolt 34 as indicated at 40.

25 if the hoisting line should break, the resulting The latch bolt 34 is provided at ts upp r end W h 25 jar on the hook would be in substantially a vertinose 35 having a am Surface 37 adapted to cal plane and might cause the heavy latch bolt gage h l wer cam fa e 3 of the pro r ion 30.

51 to compress the spring 62 and release the latch e p us iS p d With a recess 33 link arm. adapted to receive the latch nose and forming 30 It is the object of the present invention to a forward wall 39 adapted to restrain the latch 30 provide an auxiliary locking device for the latch 1105B against Opening movement lowe e bolt 5's so that a jar in any given direction can of e tc bolt 34 is p V d With a depending not accidentally release the latch link arm 44. skirt 4| adapt d to receive the pp d o Figure 1 is a side elevation, partly in cross sec- Spring The Skirt 4| is ed Slidably in a tion, of a hook embodying my improved latch recess 42 formed in the latch arm 25. The spring 35 lock. 36 is supported in the recess 42. The upper end Figure 2 is a fragmentary vertical cross section of at b 34 S guided by a roll 44 mounted on taken through the latch of Fig. 1 showing the a p n 6 secured i e latch arm 5 nd wo k n latch in the locked position. in a slot 41 formed in the latch bolt 34. The Figure 3 is similar to Fig, 2, but showing th latch bolt 34 is provided with a forwardly extend- 40 latch in the released position. ing notch 48. A downward pull on the notch 48 Figure 4 is a fragmentary front elevation, partl Compress the Spring 35 and permit the latch ly in cross section, of the latch shown in Fig. 2. link arm 25 o be disengaged f m h pr ru- Although the only part of the hook which consion 30- stitutes the present invention is the latch link The latch and lock construction described above 45 look, I will for convenience describe a complete is substantially the same as that shown in Patent hook embodying my invention, No. 1,825,018, but is described here because the The complete hook consists of a yoke l, suplatch lock 38, which is the improved feature of porting a pair of balls 2 which support a trunnion the hook, co-operates with the latch bolt 34 to 50 3. The hook shank 4 extends slidably through the p eve t acc a Opening of Sometrunnion '3 and is supported upon a coil compres- The latch lock 38 comprises a lever pivoted sion spring 5, which is supported within the housintermediate its ends to the latch bolt as indiing 5. Housing 6 is supported on an anti-friction cated at 4B. The lever 38 is received in a slot 5!] bearing 1 carried by the trunnion 3. The hook formed in latch bolt 34. The lower end 5! of lever body is indicated at 9 and is supported from the 3B protrudes from the latch bolt 34 in front of 55 the skirt 4! and is adapted to rest upon a shoulder 52 formed on the latch arm 25. A horizontal coil compression spring 54 is mounted in a recess 56 formed in latch bolt 34 and is adapted to press the lower end 5! of lever 38 outwardly so that it will normally engage the shoulder 52 and prevent the latch from being opened accidentally. In order to open the latch the lever 38 is provided with a forwardly extending finger 58 which extends into notch 48 and extends slightly above the bottom of the notch, so that a downward pull in notch 48 first swings lever 38 about its pivot 40 and moves the lower portion 5| off of shoulder 52, toward the skirt 4 l. A further downward pull on notch 48 will compress spring 36 and permit the latch to be released. The lever portion 5i is restrained against forward movement such as would move it ofi shoulder 52, by the depending guard portion 65 of latch bolt 34.

Since a hook of the type: described above is automatically closed and locked by means of a bail engaging the finger 25 in notch 23 it is necessary to provide means other than the finger 58 for moving the lever 38 off of shoulder 52. I accomplish this result by extending the upper lever arm 62 beyond the cam surface 31 of latch bolt 34 a short distance. Thus when the latch link arm 25 is in the open position the locking parts will be in the same position as when the hook is closed as shown in Fig. 2. When the closing movement of arm 25 causes the upper end of lever arm 62 to engage the cam surface 3! on protrusion 30 the lever 38 will be swung on its pivot 40 so that the lower end 5! of the lever 38 is moved off of shoulder 52. Further closing movement of the latch arm 25 is then possible and results in the latch bolt 3d being pushed down against spring 35 and permitting full closing. When the nose 35 passes the wall 39, spring 36 snaps the latch bolt 34 upwardly into locked position and spring 54 pushes lever arm 5| over the shoulder 52, thus doubly locking the latch arm 25 in the closed position.

It will be noted that the forces required for moving the two latches are exerted along lines at substantially a right angle to each other. In the present instance this is accomplished by positioning the axes of the latch springs 36 and 54 at substantially a right angle to each other, with one spring being in substantially a horizontal position. This is to insure that a shock or jar in any given direction will not unlock the latch arm 25, since only one of the locks will be affected by any given jar.

While I have shown my invention in conjunction with a hook having a closing finger 25 adapted to be engaged by a bail inserted in notch 23 to automatically close the latch arm 25, it is to be understood that my invention can be used with hooks which do not have this automatic closing feature. It is also to be understood that my invention can be used on hooks which have a latch arm pivoted to the bill to close the entrance to the bail-receiving notch whether or not the latch arm engages a protrusion on the hook body so as to carry a part of the load.

I claim:

1. In a safety hook having a body with a forwardly extending bill forming a bail-receiving notch, and a latch arm pivoted to said bill and adapted to close the entrance to said notch, a latch bolt slidably mounted on said latch arm and having its upper end adapted to engage the hook body in camming relation thereto to retract said bolt upon closing movement of said latch arm, a spring yieldably supporting said latch bolt, a latch lock comprising a lever pivotally mounted on said latch bolt and having upper and lower lever arms, said upper lever arm protruding slightly beyond the upper end of said latch bolt and being adapted to engage the hook body in camming relation thereto in advance of said latch bolt, said lower lever arm being adapted to be shiftably supported upon a shoulder on said latch arm, a spring normally urging said lower lever arm into shoulder engaging relation, and manual means for moving said latch bolt and lever to the unlocked position.

2. In a safety hook having a body with a forwardly extending bill forming a bail-receiving notch, and a latch arm pivoted to said bill and adapted to close the entrance to said notch, a latch bolt slidably mounted on said latch arm for movement in a substantially vertical plane and having its upper end adapted to engage the hook body in camming relation thereto to retract said bolt upon closing movement of said latch arm, a coil compression spring yieldably supporting said latch bolt and having its axis in a substantially vertical plane, a latch lock comprising a lever pivotally mounted on said latch bolt and having upper and lower lever arms extending in a substantially vertical plane, said upper lever arm protruding slightly beyond the upper end of said latch bolt and being adapted to engage the hook body in camming relation thereto in advance of said latch bolt, said lower lever arm being adapted to be shiftably supported on a shoulder on said latch arm, spring means normally urging said lower lever arm laterally into shoulder engaging relation and manual means for simultaneously moving said latch bolt and lever to the unlocked position.

3. In a safety hook having a body with a forwardly extending bill forming a bail-receiving notch and a latch arm pivoted to said bill and adapted to close the entrance to said notch, a latch bolt slidably mounted on said latch arm for movement in a substantially vertical plane, spring means normally urging said latch bolt toward the locked position, a latch lock pivotally mounted on said latch bolt, spring means normally urging said latch look toward the locked position, and adapted to be actuated by a force applied in a substantially horizontal direction, and manual means for simultaneously moving said latch bolt and latch lock to the unlocked position.

4. A safety hook as defined in claim 3 in which the pivoted latch arm is provided with an inwardly extending finger adapted to extend into said notch and to be engaged by a bail received in said notch to automatically close said latch arm.

5. A safety hook as defined in claim 3 in which the pivoted latch lever arm is provided with a shoulder at its free end adapted to engage a protrusion formed on the hook body adapted to carry a part of the load on the hook.

RICHARD K. HER'I'EL. 

